Hi,
In ChainMap example
c = ChainMap() # Create root context
d = c.new_child() # Create nested child context
e = c.new_child() # Child of c, independent from d
e.maps[0] # Current context dictionary -- like Python's locals()
e.maps[-1] # Root context -- like Python's globals()
e.parents # Enclosing context chain -- like Python's nonlocals
d['x'] # Get first key in the chain of contexts
d['x'] = 1 # Set value in current context
d['x'] - will raise key does not exist error
so simple fix is to flip last two lines...
I know, possibly anal but look love Python and would like to help new folks to not get confused if they play with example in cPython shell...
--best

I will flip the two because there is not downside. However, the table of wasn't intended to be a sequential example (that's why there is no data or display of result). Instead, it was just meant to be table of typing-this-does-that.